Field of the Invention
The present invention relates to a method of obtaining the position of a shot region formed on a substrate, an exposure method, and a method of manufacturing an article.
Description of the Related Art
One of apparatuses used in the manufacturing process (lithography process) of a semiconductor device or the like is an exposure apparatus (lithography apparatus) which transfers the pattern of a mask (original) to a substrate (for example, a wafer or glass substrate) coated with a resist (photoresist). The exposure apparatus needs to transfer the pattern of a mask at high accuracy to each of a plurality of shot regions formed on a substrate. It is important to align the pattern of the mask and each shot region at high accuracy. In the exposure apparatus, the positions of a plurality of marks arranged in each of a plurality of shot regions are detected prior to exposure. Based on the detection result, accurate positions in each of the plurality of shot regions formed on the substrate are measured.
The exposure apparatus also needs to improve the throughput (productivity). In the exposure apparatus, it is therefore important to shorten the time (measurement time) taken to obtain the positions of a plurality of shot regions formed on a substrate. Japanese Patent Laid-Open No. 10-284396 has proposed a method of shortening the measurement time by detecting a plurality of marks on a substrate so as to shorten the moving distance of the substrate, instead of detecting the marks by moving the substrate in each shot region. Japanese Patent Laid-Open No. 2001-223150 has proposed a method of, when detecting the position of a mark arranged in a shot region on a substrate, shortening the measurement time by applying a focus value used when the position of a mark on another substrate was detected.
In the method disclosed in Japanese Patent Laid-Open No. 10-284396, a plurality of marks on a substrate are merely detected to shorten the moving distance of the substrate. Thus, the measurement time can be shortened by only a decrease in the moving distance of the substrate. Japanese Patent Laid-Open No. 2001-223150 does not disclose a method of, when obtaining the position of a target shot region, applying the position of a mark arranged in a shot region formed next to the target shot region on the same substrate.